<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>表格中的空单元格</title>
</head>
<body>
<table border="1">
  <tr>
    <td>row 1, cell 1</td>
    <td>row 1, cell 2</td>
  </tr>
  <tr>
    <td></td>
    <td>row 2, cell 2</td>
  </tr>
</table>
</body>
</html>